Refrigerating-machine.



D. 0. SMITH.

RBFRIGERATING MACHINE.

APPLICATION FILED JUNE 29, 1911.

v 1 ,038,221, Patented Sept. '10, 1912.

umrsn STATES hams]: o. sir-ma, or Minronn, comrnc'rrcu'r, ASSIGNOB- 'ro SMITH nnrnmnnarnm" "PA ENT OFFICE,

I COMPANY, OF NEW ORLEANS, LOUISIANA, A CORPORATION OF LOUISIANA.

To all whom magjz'oncem:

Be it known that I, DANIEL C. .Srrrrma citizen of the United States of America, :Th

formerly a resident oi Brooklyn, New York, and now a resident of Milford, Connecticut, have invented fcertain new and useful Improvements in Refrigerating-Machines, of

which the following is a specification.

My invention relatesto improvements in refrigerating machines and apparatus. 'The refrigerant which I employ is preferably operation, and to ammonlmand my invention has special reference to apparatus for employment in those processes of refrigeration which are characterized by the distillation ot ammonia from ammonia water,.the condens1ng and storing of the ammonia under pressure, the expansion of the ammonia in a refrigeratlng element such as an expansion coil, and, cyclically, the re-absorption of the ammonia by the water residue of the distillation. It has been proposed to conduct such processes without resort-to mechanical power-actuated accelerating or relaying devices, such as circulating and compression pumps; but up to this time,as I am informed, no project I of the kindhas ultim'ated in any process of ,apparatus of a practical or commercial nature. The common purposeof inventors in this branch of the arthas been to avoid the employment of movingparts, pumps and the'like, and, generally, to avoid the use of machinery and apparatus which would require expert. knowledge or skill for its would be reliable, safe, eflicient, economical, and yet be simple. and cheaptomanufacture. Thesehave also been my objects, yet .up to. the time of making. the invention and disooveries herein disclosed, my experiments, were productiveionly of processes and apparatus which were uncertain and unreliable, and which, if; pprorimately safe, were .not efficient; and, If'approximately eiiicient, were most dangerous and unsafe, even in the hands of persons thprou'gh'ly familiar with the art,

The. apparatus or machine constituting the subjectelhatter of this application comprises a number of constantly closed receptacles joined a simple system of pipes and which,;eizcept fora few valves in said pipes,.is 'free from moving parts.- This apparatus'is r'gliable as to results to be secured from time "to' time; is etfieient and economiprovide apparatus which 5 nnrnrenaarme-maonmn.

Specification of matters Patent. Patented s g jqs igjg Application filed men, i911. Serial in. 635,996.

tensive refrigeration.

so by factories and plantscalling for more eX-,.

I attain reliability in operation by securing a substantially anhydrous distillate at. l each distillation of the ammonia water, and I by maintaining the'ammonia water in maximum absorptive condition'during refrigeration. The from this-obtainance and use of anhydrous; lammonia, coupled with the advantages attained by securing a maximum quantity of distillate from a minimum ofheat expended, and which also result in the re-absorption thereof during refrigeration. p Q Economy is assured" by the small con-' ,sumption of heat, by the simplicity of the apparatus, and by the general avoidance of fparts which would require more attention I or a higher degree of skill on the part of the user.

I attain safety by employing a completely closed system and, more particularly, by ;const-ructing the apparatus in such manner as to avoid and ;acc'umulation of. bodies of eithersteam o'r efliciency of my invention arises prevent the formation on ammonia gas in that part of the system in which the distillation of the ammonia is i initiated and to which heat at high temperature is necessarily applied. r i 3 As more fully explained hereinafter, I iattain these desirable and necessary etiects l and advantages chiefly by the manner in ;which I treat and manipulate the ammonia f water at times of distillation and at times of, absorption; that is, at times of distillation' I 5 treat and manipulate the ammonia waterin' such manner as to substantially preclude gthe escape of steam fronr the ammonia and in the same manner, I preclude thees-f cape of ammonia gas from the ammonia water. By insuring the complete absorption of the returned ammoniml make it possible .to maintain an .efiic'ient vacuum abovethef ammonia water, and *hence permit .grea-te'i expansion of the ammonia gas. As will ap pear hereinafter, a partial vacuum is created j by the cooling ot'the ammonia water in the water; and, during the absorption period,v

interval between di sftillat-ion a-nd absorption, I

ifand by preventin the escape of ammonia on during absorption the effect of this partial vacuum is preserved until the water becomes saturated. I divide the requisite quantity of ammonia water primarily into upper and lower bodies, in closed containers or tanks at different elevations, and place them in. siphonic circulatory connection by means of suitable pipes or conduits; Whenever the temperature of the liquid in the lower tank exceeds that of the liquid in the upper tank or when the states of saturation are different, the liquid, through differences in specific gravity, will rise from the lower tank into the upper tank, and the cooler or heavier liquid in the upper tank will fall or flow downward into the lower tank to replace the lighter liquid rising therefrom. Thus the lower tank is always kept full of liquid. This circulation takes place in both the distilling and the absorb-.

mg steps. or periods, differences of temperature existing at both times; for, as hereinafter explained, I apply heat to the lower tank, to distil the ammonia; and in the absorbing period I admit the ammonia gas to the lower tank and hence the lower body of liquid is the first to receive the heat liberated therefrom. The rapidity of the circulation is primarily induced and determined by the differences of tci'nperaturc in the two tanks, and in the several parts there of, but is augmented or accelerated by two forces which operate during the distilling and absorbing periods, respectively, said forces being local differences of pressure in the two tanks. ,,Ihe first of these differences of pressure is occasioned bv the vapors and gases that are rapidly evolved when the lower tank is externally heated, and the sec- 0nd difference of pressure is induced by the heat given off in the lower tank when the ammonia gas recombines with or is absorbed by the water; aided by the partia vacuum which I: am careful to create and maintain above the liquid in the upper tank prior to and substantiallythroughout the absorbing period.

The described circulation of the liquid hastens the liberation oft he ammonia gas from the ammonia water when the lower tank is heated, and at the same time prevents the attainment of dangerous temperatures or pressures. When the hot liquid rises from the lower tank, its temperature often sutlicicnt to a dm'it of the presence of steam bubbles, but in circulating through the pipes and in being diffused in the cooler water in the upper tank, much of this heat is lost by heat radiation and absorption, and the steam is immediately condensed and not permitted to pass oil? with the ammonia gas. This goes farto explain the reliability and clliciency, of my apparatus, for it follows that the gas which is cvolicd or distilled is substan lially anhydro I W'l iilc in ainlower tan .seal' the upper tank against the entrance of taining in the upper tank a temperature which causes the condensation of the steam, I at the same time hold that temperature at such a point that there is substantially no re-absorption of ammonia gas in the upper tank after'the first few minutes of distillation; this adds much to the eflicieney of the apparatus inasmuch 'as waste of heat is thereby avoided. Similarly, the described circulation of the liquid, durin the absorption period, insures the rapid issipation or radiation of the heat caused by the absorption or recombination of the ammonia gas with the water, and also insures the retention of the free gas in water until combination or absorption is complete. I place little if any reliance upon the surface absorption of gas by the water in the upper tank, and on the contrary am careful to keep the gas immersed in the water until it is absorbed to the end that the vacuum before referred to may be maintained substantially throughout the absorbing period, and efficiently, until the water has reached a state of substantially complete'saturation with ammo-- steam during the distilling operation, and

to create and maintain the partial vacuum in the upper tank after distilling and during the a sor tion period, I am careful to prevent the rec discharge of either ammonia water, steam or gas into the upper part of the upper tank, that is, above the surface of the liquid therein. In other words, I confine the circulation to and within the bodies of the liquid. I accomplish this by means of one of the pipes before referred to, which pipe rises from the lower tank, enters the upper tank, and opens below the surface of the liquid therein. That is, I insure such condensation, and insure and maintain the described vacuum by extending this pipe downward in the upper tank, to a point considerably below the surface of the li uid therein. The pipe which conducts the iquid from the upper tank to the lower tank extends from the lower part of the upper tank to the lower part of the r In this manner I effectually steam or gas except; through the medium of the liquid contained therein. in the elimination of steam from the distillate during the distilling operation, and further results in preventing the rise of vapors or gasinto the vacuum space in the upper tank during the absorption period,

the gases as before stated being held in a This results messes aisle oi submersion admixlluie will! the normal conditions, the water has reached a state of substantial saturation. .And by mainisining such psi'biel vacuum ovoid the heel: pressure which has been one of the moss objectionable features oi pxeviously proposed processes and apparatus. will now be clear that steps end the rhesus Whichl employ to insure the condensstiou of water vs orsnd consequent dehydration of the disti led gas are identical with the steps and means which I perform and employ 'to insure and presei've the described vacuum during the absorption period.

I employ a condenser to receive the gas from the upper tank, and this condenser delivers .the liquid ammonia inio a reservoir. The reservoir is in turn connected to e 1efrigerating element, such as e. refrigerating coil, and a return pipe joins the latter to the lower tank. A valve is interposed between the upper tank and the condenser. Another valve is interposed between the reservoir and the refrigerating coil, and a third valve is interposed between the refrigerecing coil and the lower tank. Bei'o se beginning the distilling operation, I close all these valves. W hen the pressure in the tanks rises to point. where it exceeds approximately ninety gounds, and exceeds the p essure in the reservoir, without which the gee would not flow toward the l'l%!V0li, I open the valve between the upper tank and the condenser, and put the condenser in operation. The condenser remains in operation until distillation has been completed, whereupon. said valve is closed and the host is withdrawn from the tanks. At: this siege 1 allow the tanks to cool until the liquid contents thereof has assumed a. normal bempei'stui'e. As the tanks are completely closed during this period, the cooling and condensation of the conlenis causes the formation of o partial vacuum in the top of the upper tank and in the pipe leading therefrom to the condenser valve. Upon the appearance of a vacuum, observed by any suitable means such an ordinary gage, refrigeration and absorption may be started; At this time I slighily onen the valve between the reservoir and the coil and permit the liquid ammonia to expand or gssify therein. At the same time i open the valve between the coil and the lower tank so that the expanded ammonia may pass back into that tank- The ammonia, expanding within the, coil, reduces the temperature thereof; accomplishing the refrigeration which is the end and aim of the invention.

When, through absorption, the liquid in the isnks becomes saturated, the anther relam; flow of expended will an ccieclively absorbed. Furl-lies, the

placed above the liquid tank.

conclusion of cui olus in so she vacuum W l c-e deseroyed. The lion. cl vocuiuu by the accumulation of gas, in the ion of she un ess tank it cuts prio? o Elie substenbclly complete ration or he writes; and in is use o tulle place when the reservoir valve is Widely opened as permitthe gas to u back so she tanks in such lscge volus e as induce C. to thereby greedy seduce the sbsorpeivc cspscily of: lhe water. in s. practical set so, the destnaeiion of use vacuum normally masks the of she refrigemlviog opossiion, inesmuch "es i'usclaex gas from the l ii'igei'eting coil will not thereafter be .L door of wees costumed, back pressure would quic y build up and limit the sion of the arc-monies gas in the coil. In e case of sppsretus of ordinary dimensions, the absorption extends through many hours, whereas distillaiion be accomplished in. a much shorter lime. t the end of the absorption period, 1 again close all she valves before referred to, end heal: the lower tank to insiiiute s new distillation. of the ammonia Weiss.

My invention will be more readilyv undersiood by reference to the accompanying drawing, forming past of ibis specifimtion,

and in which 1 have depicted an apparatus or machine of simple and preferred form.

Figure 1 of the drawings is s plan view of such apparatus. Fi 2 is a side View j theleof, the condenser, i:- ie reservoir, the refiigerating coil and the return pipe being shown diagrammatically; it should be understood that in prcclice the coil is always Fig. 3 is a vertical transverse section of the lower and upper tanks and the circulation pipes.

The process herein disclosed is not claimed in this application, being fully described and claimed in my copending application. filed June 8th, 1911, Serial l lo. 631,933.

In the drawings, 7 represents the" lower tank. This is preferably of considerably less diameter than length and occupievshoriscrotal pos"i0i1. Beneath the tank is a heater, prei'eiiably, a gas pipe 5 having burn as 6 and a. regulating valve As indi- U ccted in the drawings, I may subdivide the upper tank into two or more smaller tanks and thereby relatively increase the radiating surface. In she present case there are three such tanks indicated by the nunrieml 8. These tanks are also arranged horizontally and are preferably parallel with one another and transverse to the longer lower tan-k. These tsnlis 8 collectively constitute the upper tank before referred to, and each thereof is connected with the lower tank by Cll'filllosing pipes which perform the functions before described. Above the tanks 8 is s measure therein and header 15. Pi es 14, 14 extend, preferably, from points about midway of the tank 7, through the top of the tank 7, and at their u per ends join the header-15. The portions of the pipes 14 which are within the tank 7 contain erforations 14 to facilitate the entrance 0 liquid thereto and prevent the accumulation of either steam orgas in the upper part of the lower tank. Pipes 16, 16, 16 extend downwardly fronr'the header, through the tops of the tanks 8, and down wardly therein to points near-.the bottoms thereof. The pipes 14, 15, 16,'the inclosing tank 8, and the pipes 21, 12, constitute an effective siphon, which insures the ra )id interchange of cool water from tank 8 or the warmer liquid from tank 7. As clearly shown in Figs. 2 and 3, each pipe 16 has its lower end equipped with a cross pipe 61 whichis perforated and constitutes a diffuser. One or more .pipes 12 extend downwardly from each tank 8 apd are joined to and communicate-with the lower part of tank 7. The pipes 12, as shown in Fi 3, extend within respective tanks B and t .eir inner ends are perforated as showm at 21. The pipes. 14, 1.5, 16, 61, 21 and constitute the circulating pipes or ducts before-referred to. r

18 is the gas exit ipe. It is connected with each tank 8 and the openings 18 leading from the tanks 8 to the pipes 18 are all above the highest level attained by the liquid in the tanks during the operation of the apparatus.

19 is the condenser and 20 isthe condenser valve. The condenser may comprise a simple water jacket forflowing water and an ordinary condenser coil 21 indicated by dotted lines in Fig. 2.

23 is the reservoir, which is joined to the condenser coil by a pipe 22.

11 represents the refrigerating coil, and 24 is theexpansion valve which is interposed between the reservoir and the coil.

9 represents the return pipe and 10 is the valve which is interposed between the re frigerating coil and the lower tank 7. The

pipe 9 extends through the end of the tank 7 and to the other end thereof, being disposed near the bottom of the tank 7. The portion of the pipe 9 which lies within the tank 7 contains a large number of small perforations for diffusing the gas. It should be understood that all joints between the tanks and pi es are tight joints, and that the tanks, coi s and reservoir are closed, and constructed to withstand high pressures.

One way in which to prepare the appara tus for use consists in closing the valves 10 and 20, then temporarily opening the header 15 and filling the tanks 7 and 8 and coin nected pipes with ammonia water, up to a working level in the upper tank. The air remaining in the upper tank may be then exhausted and the header closed. When this is accomplished, the apparatus will be found ready for use. A the valves being closed, the gas may be lighted under the tank 7. Obviously, the liquid which is in contact with the bottom and side walls of the tank 7 will be quickly raised in temperature. This heated liquid havlng no other escape will rise through the pipes 14 and then descend into the tanks 8 through pipes 16 and 61. As the hot liquid rises 111 this manner, it is replaced by the cooler liquid which flows into the tank 7 through the diffusers 21 and the pipes If]. As the temperature of the liquid increases, gas will.

be liberated and when the pressure in the tankbecomes approximately ninety pounds, which appears to be the minimum condensation pressure, the valve 20 may be opened to permit the gas to escape from the tanks 8 and flow into the.condenser. At this time the condenser coil is cooled, and through the action of its low temperature and the pressure of the gas, the latter is condensed and flows into the reservoir -23. It will be ob-] served that the gases evolved in the upper tank or tanks, due to a sufiicient rise of team perature therein, may bubble upward through the liquid therein and thence pass directly to the condenser. By reason of heat radiation, the temperature of the upper tank is never sufiicient togenerate steam at the pressure existing therein, hence gases initially distilled in the upper tank are substantially free from water. It will be further observed that all steam and gas which as ccnd with the water in riser pipes 14 are discharged into the tanks 8 through the sub dividing and admixing perforations of the pipes 61 located near the bottoms ofthe tanks 8, and hence relatively far below the surface of the liquid therein. By reason of the relatively low temperature in the tanks 8 all steam thus discharged therein is immediately condensed, while the gas thus discharged may find escape at the surface of the liquid. In this manner I insure the effective dehydration of the distilling gases prior to their exit. through the pipe 18. The substantially uniform withdrawal of the liquid from the several portions of the tanks vportant effect of refrigeration in the coil *11; .At this point I' call attention to the large lnea aal,

, amount of radiating surface presented by the upper and lower tanks and circulating pipes. Gircu'lation obviously continues after the heat is shutoff, and the heat is dissipated g quickly so that only a short time is required to reduce the weak liquor to a temperature admitting efl'ective absorption of the gas.

As the gasv enters the tank 7 through the perforated portion of the pipe 9 it is sub- 19 divided into a great number of streams of minute bubbles, and quickly enters into qmbination with the water. This combination gives off heat, and through the rise of temperature thus occasioned an activecircu- 3,5 lation of the liquid is set up in the circulating pipes and tanks. As the liquid which contains the bubbles ofgas ascends through the I pipes 14 and thence into the upper tanks through the difl users, the liquid is thoroughly agitated and admixed with the "gafi and. the latter is thoroughly ditl'used in the liquid contents of the up er tanks. It is to be assumed, therefore, t at very little of the gas returns to the lower tanks 35 through the down or fall pipes 21, 12. The perforated pipes or difl'users in the tanks 8 obviously cause the breaking up of the'gas bubbles and the absorption of the gas by the water. As best shown in Fig. 3,1 prefar that the fall ducts or pipes 12 shall discharge at points immediately adjacent to the region of the admission of gas to the tank 7, for the purpose of keeping down the temperature of the water surrounding the perforated pipe 9. Absorption goes on in this way'until the whole body of liquid in the tank'is saturated with ammonia, where,- upon the-valves 24 and -10 may be again closed preparatory, to the, next heating of the liquid No danger and no bad results attend any mismanipulation of the valves or of the heat.

j ,Having thus described my invention, I claim as new and desire to secure by Letters Patent:v f

L- The herein described ammonia absorption refrigerating apparatus, comprising upper and lower close; tanks to contain a requisite quantity of ammonia water, in combination with a valved gas outletfor the upper tank, a valved gas diffusing inlet for the lower tank,"means for heating the contents of the lower tank to a higher temperature than the contents of the upper tank and siphonic circulating and difi'using ducts, together establishing a closed liquid circuit within and between said tanks and insuring the difi'usion in the cooler liquid contents of the upper tank, of liquid, vapors and gases :50 heated, evolved or diffused in the lower tank,

whereby substantiall anhydrous ammonia gas may be dist-file under pressure and subsequently re-absorbed under a partial as ac um! 2- he herein ammoniaabsorp 4 means for heating the contentsof the lower tank to a higher temperature than the contents of the upper tank and siphonic circulating and diiiusing ducts, together establishing a closed liquid circuit within and between said tanks, limiting initial evolution anddifiusion of vapors and gases to the liquid contents of-thalower tank, and insuring subsequent diffusion in the cooler liquid contents of the upper tank, of liquid, vapors and gases from the lower tank, whereby substantially anhydrous ammonia gas ma be distilled under pressure and substantially re-absorbed under a partial vacuum.

3. The herein described ammonia absorption refrigerating apparatus, comprising .a lower closed tank and an upper closed tank, together adapted to contain a requisite quantity of ammonia water, in combination with riser and fall ducts joining said tanks, said riser duct arranged to lead ammonia water, steam and gases from the upper part of said lower tank into the ammonia water in said upper tank, and said fall duct an ranged to lead ammonia water from alower part of'said upper tank into said lower tank, a valved gas outlet for said upper tank, a

valved gas inletduct for the lower tank, and a heater associated with said lower tank, whereby substantially anhydrous ammonia gas may be distilled under pressure and subsequently re-absorbed under a partial Vacuum.

4:. The herein described ammonia absorp tion refrigerating apparatus, comprising a lower closed tank and an upper closed tank, together adapted to contain a requisite quantit of ammonia water and a free space a ove the water, in combination with riser and fall ducts joining said tanks, said riser duct arranged to lead ammonia water, steam and gases from the upper part of said lower tank and deliver it onl intothe ammonia Water in said upper ta and said fall duct arranged to lead and direct ammonia water from the lower partnf said upper tank into the lower part of said lower tank, a valved gas outlet for said upper tank,

a valved gas inlet for the lower tank, and, a heater associated with sai lower tank, whereby substantially anhydrous ammonia gas may be distilled under pi-Essure and subsequently re-absorbed under a partlal vacuum.

5. The herein described ammonia absorption retrigeratmg' apparatus, comprising'a lower-closed tank and an'upper closed tank, together 7 adapted to contain a requisite Quantity at amnesia water, 121 combination with riser and fall ducts siphonically joining said tanks, said riser duct arranged to lead ammonia water, steam and ases from the uglper part of said lower tan and diffuse t e same in the ammonia water in said upper tank, and said fall duct arranged to lead ammonia water from the said upper tank and direct the same into the lower part of said lower tank, a valved gas outlet for said upper tank, a valved gas inlet for the lower tank, and a heater associated with said lower tank, whereby substantially anhydrous ammonia gas may be distilled under pressure and subsequently re-absorbed under a partial vacuum.

6. The herein described ammonia absorption refrigerating apparatus, comprising a closed heat absorbing and radiating ammonia water tank, in combination with a second closed heat radiating and vacuum ammonia water tank, a diffuser arranged in said second tank below theworking liquid level therein, a riser duct leading from the first tank to the difluser within the second tank, a fall duct leading from the second tank and arranged to direct the liquid therefrom into the lower part of the first mentionedtank, a valved ammonia outlet for said second tank, a valved ammonia gas inlet for said first tank, and a heater associated with said' first tank, whereby substantially anhydrous ammonia gas may be distilled under pressure and subsequently re-absorbed under a partial vacuum.

7 The herein described ammonia absorption refrigerating apparatus, comprising a lower heat absorbing and radiating closed tank, in combination with an upper heat radiating and vacuum closed tank, said tanks together adapted to contain a requisite quantity of ammonia water without completely filling said upper tank, a diffuser arranged in said upper tank below the working liquid level therein, a riser duct leading from the upper part of said lower tank to said diffuser, a fall duct leading from said upper tank and arranged to direct the liquid therefrom into the lower part of the lower tank, a valved ammonia gas outlet for said upper tank, a valved ammonia gas difiuser in the lower part of said lower tank, and a heater associated with said lower tank, whereby substantially anhydrous ambe distilled under pressure monia gas may under a parand subsequently re-absorbed tial vacuum.

8. The herein described ammonia absorption refrigerating apparatus, comprising a lower heat absorbing and radiating closed tank, in combination with a plurality of upper heat radiating and vacuum closed tanks, said tanks together adapted to contain a requisite quantity of ammonia water without completely filling said upper tanks, a diffuser arranged in each upper tank be- .ing from low the surface level of the liquid therein, a riserduct or ducts leading from the lower tank'to each said diffuser, a fall duct leadeach upper tank and a to direct the liquid therefrom into the over part of the lower tank, a valved ammonia ppertanks,n

gas outlet common to said u I difluser m and lower valved ammonia gas tank, and a heater associated with Said lower tank, whereby substantially anhydrous ammonia gas may be distilled under pressure and subsequently re-absorbed under a partial vacuum.

9. The herein described ammonia "absorption refrigerating apparatus, comprising a lower heat absorbing and radiating closed tank, in combination with a pluralit of upper heat radiating and vacuum 'c osed tanks, said tanks together adapted to contain a requisite quantity of ammonia water without completely filling said upper tanks riser ducts leading from the upper part of said lower tank and dischargin into said upper tanks below the working fiquid level therein, a fall duct leading from the lower' partof each upper tank and arranged to direct the liquid therefrom into the lower part of the lower tank, a valved ammonia gas outlet common to said upper tanks, 3 valved ammonia gas difi'user in said lower part of said lower tank, and a heater associated. with said lower tank, whereby substantially janhydrous ammonia gas may be distilled under pressure and subsequently re-absorbed under a partial vacuum.

10. The herein described ammonia absorption refrigerating apparatus, comprising a lower closed tank, a combination with an upper closed tank, diffusing means arranged in said upper tank below the working liquid level therein, siphonic ducts connectin said tanks and co-acting with said di using.

means in thesaid upper tank, a valved ammonia gas outlet for said upperi tank, a valved ammonia gas inlet. for said lower tank, and a heater associated with said lower tank.

11. The herein described ammonia absorption refrigerating apparatus, comprising a horizontally elongated closed tank, in combination with a horizontally elongatedsec- 0nd closed tank above the same, riser and fall ducts siphonically connecting the lower portion of the second tank with the ugiper and lower portions, respectively, of the mentioned tank, a valved gas outlet for said second tank, a valved gas inlet for said first tank, and a heater associated with said first tank.

' the first mentioned tank, difl'users in said mentioned tank, a difiuser in said second tank and co-acting with said riser duct, a'

valved gas outlet for said second tank, a valved gas difiuser in the lower part of said first tank, and a heater associated with said first tank.

13. The herein described ammonia absorption. refri crating ap aratus, comprising a horizonta y elongate closed tank, in combination with a plurality of horizontally elongated closed tanks arranged above the same, ducts siphonically connecting the lower portions of the upper tanks with the upper and lower portions, respectively, of

upper tanks and co-acting with respective ducts, a valved gas outlet for said upper tanks, a valved gas difiusing inlet pipe disposed in the lower part of said first tank, andkaheater associated with the said first tan 14:. The herein described ammonia absorp- :tion refrigerating apparatus, comprising a lowerhorizontally elongated closed tank, in connection with an upper horizontally elongated tank, riser and fall ducts extending between and siphonically connecting the two tanks, a horizontally disposed diffuser or distributor at the discharge end, of the riser duct in the upper tank and helowthe working liquid level therein, a valved gas outlet for the upper tank, a valved gas diffusing inlet ductin the lower tank, and heating means associated with said lower tank.

15. In an ammonia absorption refrigerating apparatus, juxtapositioned closed tanks to contain a requisite quantity of ammonia water, in combination with a valved ammonia gas inlet for one said tank. a valved gas outlet for the other, means for heating the tank having the gas inlet, ducts establishing circulatory communication between said tanks, and so disposed as to restrict circulation to and within the Wat r therein, and means difiusing the flow 0 water to and from said ducts.

16. The herein described ammonia distilling apparatus, comprising upper and lower closed tanks to contain'a requisite quantity of ammonia water, means for heating the contents of the lower tank to a higher temperature than the contents of the upper tank, and a valved gas outlet at the top of the upper tank, in combination with siphonic circulating and diffusing ducts completing a closed liquid circuit within and between said tanks and insuring the difiusion in the cooler liquid contents of the upper tank, of liquid, vapors and gases heated and evolved in the lower tank, whereby sub' tantially anhydrous ammonia gas may be distilled under pressure.

17. The herein described ammonia absorption refrigerating apparatus, comprising upper and lower closed tanks to contain a requisite quantity of water, in combination with a gas difl'using inlet in the lower part of the lower tank and siphonic circulating till and difiusing ducts, together establishing a- I closed liquid circuit within and between said tanks and insuring diffusion in the cooler liquid contents of the upper tank, of gases not absorbed in the lower tank, whereby ammonia gas may be absorbed under a partial vacuum.

In testimony, that I claim the foregoing as my invention, 1 have signed my name in presence of two subscribing witnesses.

DANIEL C. SMITH, Witnesses L. Dons-ran, JOHN lilnn'reen. 

